This invention relates to a data storage system which serves a number of user circuits each of which provides one of the ports to the system and over which messages may be received either for transmission or retransmission, or for temporary storage, or for processing at the user circuits.
Each such message includes signalling information and address information, and the system is applicable to, but by no means restricted to, a message transmission system included in a digital telecommunication system having many system nodes, which in one example of such a system are telephone exchanges or system administration centres.